In isolated energy systems, such as, but not limited to, offshore platforms and vessels, intense power consumption processes, such as drilling processes, use large amounts of energy to operate e.g., drilling rigs and heave compensation systems. Significant amounts of electrical energy may be generated by electric dynamic braking (so-called regenerative brakes). Braking resistors may in the electrical system be used to burn off surplus energy in e.g. DC links for variable speed drive systems. This energy is in offshore platforms and vessels dumped through air or water cooling systems (such as seawater or air cooled braking resistors).
Further, isolated energy systems, such as modern drilling rigs and drilling platforms, designed for cold climates consume large amounts of heat for de-icing, general utilities and heating, ventilation and air conditioning (HVAC) systems. This heat is traditionally mainly generated by oil-fired steam generators, steam boilers, or hot water boilers.
In existing offshore platforms and vessels the energy consumption system is not related to the energy generation system. Thus any mutual benefits from these systems are lost.
WO2011148050 discloses a rock drilling rig, a method for transfer drive of the rock drilling rig, and a speed controller. It is noted that surplus electric energy generated in deceleration may be converted to thermal energy in electric brake resistors. In addition to this, by means of the surplus electric energy produced in deceleration it is possible to operate one or more hydraulic systems in the rock drilling rig, whereby all the surplus electric energy need not just be wasted through brake resistors.
US 2010/133031 A1 relates to a hydraulic hybrid power system for a hydraulic hybrid vehicle where a pump is driven by one or more wheels of a hydraulic hybrid vehicle during braking. According to paragraph 7, when additional power is required by the vehicle, the liquid is released into a heat exchanger that transfers heat from the exhaust gas of the heat engine to the liquid causing at least a portion of the liquid to become gaseous.
However there is still a need to provide improved energy accumulation and distribution.